The present invention relates to a cylindrical linear motor having a cylindrical rotor that has eight poles and further having a cylindrical stator with a winding made of 36 toroidal coils that extend in the circumferential direction.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
Linear motors can have a cylindrical design. The stator core is therein embodied hollow-cylindrically and on its inside has slots extending in the circumferential direction. Inserted into said slots are toroidal coils. The stator core is usually made from a solid, magnetically soft material.
The rotors of the linear motors are typically fitted on their surface with permanent magnets. The stators of the linear motors dynamically form the magnetic poles in the axial direction. The rotor and stator will then attract each other with different forces depending on the axial position. This produces in part high cogging forces which are undesirable in linear motors.
Combination drives are employed for drive functions requiring a rotating and linear motion. Advantageously, angle and travel of these motions can be freely and mutually independently set. There motions must frequently be performed highly dynamically.
It would therefore be desirable and advantageous to obviate prior art shortcomings and to provide an improved cylindrical linear motor having very low cogging forces.